1. Field of the Invention
The present invention relates to a structure of a speaker and a method of assembling the speaker. More particularly, the present invention relates to a structure of a slim speaker and a method of assembling the slim speaker.
The present application claims priority from Japanese Application No. 2000-235544, the disclosure of which is incorporated herein by reference for all purposes.
2. Description of the Related Art
FIG. 6 is a sectional side view showing a structure of a conventional speaker.
The conventional speaker illustrated in FIG. 6 has a casing composed of frames 1A, 1B. In the casing, a voice coil bobbin 3 is supported vibratingly in the axial direction by a damper 2 which is interposed between the voice coil bobbin 3 and the frame 1A.
A voice coil 4 is wound on the outer periphery of the voice coil bobbin 3. Portion of the voice coil bobbin 3 on which the voice coil 4 is wound is inserted into a magnetic circuit gap g between a yoke 7 on one side and a pole piece 5 and magnet 6 on the other side, all of which form a magnetic circuit. The magnetic circuit causes the voice coil bobbin 3 to vibrate in the axial direction.
Referring to FIG. 6, a cone paper 8 and an edge 9 which is supported by the frames 1A, 1B are provided.
For assembling the speaker, as illustrated in FIG. 7, the magnetic circuit system assembly M and the vibration system assembly V which make up the speaker are assembled separately, and then combined with each other in the final process.
In this event, the voice coil bobbin 3 of the vibration system assembly V is inserted into the magnetic circuit gap g of the magnetic circuit system assembly M such that the voice coil 4 is placed at a position located at required distance from the yoke 7 and the pole piece 5 and magnet 6.
The conventional speakers as described above, however, have a problem associated with the difficulty of positioning the voice coil bobbin 3, vibratingly supported by the damper 2, to the magnetic circuit gap g when the voice coil bobbin 3 is inserted into the magnetic circuit gap g during the process of combining the magnetic circuit system assembly M and the vibration system assembly V.
Hence, in the conventional speakers, since it is difficult to determine the exact dimensions of the magnetic circuit gap g, for assembling, the magnetic circuit gap g is required to be wide. This requirement is an obstacle to an increase in an efficiency of vibration of the voice coil bobbin 3, which is caused by the magnetic circuit, to fabricate a speaker having beneficial properties.
In addition, the conventional speakers have a problem associated with increased manufacturing costs because of the separate processes for assembling the magnetic circuit system assembly M and the vibration system assembly V, as described above.
The present invention has been made to solve the above problems associated with such a conventional speaker.
It is therefore a first object of the present invention to provide a speaker in which exact dimensions of a magnetic circuit gap, into which a voice coil bobbin is inserted, are determined, thus creating beneficial properties.
It is a second object of the present invention to provide a speaker which reduces the manufacturing costs.
To attain the above first object, a speaker according to a first aspect of the present invention includes a voice coil wound on a voice coil bobbin and inserted into a magnetic circuit gap of a magnetic circuit, and a diaphragm member linked to the voice coil bobbin and vibrated. Such speaker features in that the diaphragm member is constructed of two divided vibration members of a first divided vibration member linked to the voice coil bobbin and a second divided vibration member linked through an edge to a frame.
According to the speaker of the first aspect, the diaphragm member, which vibrates to output sound, is designed as a two-piece member made up of the two divided vibration members: the first divided vibration member and the second divided vibration member. For this reason, during assembly, the voice coil bobbin linked to the first divided vibration member can be joined to the magnet circuit part made up of a yoke and a magnet, while being separated from the damper and the edge which are to elastically support the diaphragm member.
Hence, when the portion of the voice coil bobbin on which the voice coil is wound is inserted into the magnetic circuit gap formed in the magnetic circuit part, the voice coil bobbin can securely be positioned to the magnetic circuit gap. This eliminates the need for providing large dimensions for the magnetic circuit gap for assembling as in the prior art, and allows the dimensions to be set at the minimum values needed for vibration of the voice coil bobbin, resulting in accomplishment of the high efficient configuration of the magnetic circuit.
Further, the two-piece member designed for the diaphragm member allows the speaker to be assembled while the individual parts are constructed sequentially in the single assembly line, which results in an increase in the efficiency of the assembling operation.
To attain the aforementioned first object, a speaker according to a second aspect features, in addition to the configuration of the first aspect, in that the diaphragm member is a cone member. With this configuration, the speaker using the vibration of the cone member for output can have a high efficient magnet circuit configuration and also have an efficient assembling operation.
To attain the aforementioned first object, a speaker according to a third aspect features, in addition to the configuration of the first aspect, in that a plurality of dampers are interposed between the first divided vibration member and the frame.
According to the third aspect, due to the two-piece member designed for the diaphragm member, the second divided vibration member can be mounted after the mounting of the plurality of the dampers. This allows the slim speaker to employ, for example, a double damper, which has conventionally been difficult. Hence, the vibration system is prevented from decentering or inclining at large amplitude, resulting in improvement of the resistance to input.
To attain the aforementioned first object, a speaker according to a fourth aspect features, in addition to the configuration of the third aspect, in that the first divided vibration member and the second divided vibration member are linked to each other through the damper interposed between the first divided vibration member and the frame. With this configuration, the first divided vibration member and the second divided vibration member are supported by the dampers and vibrated concurrently.
To attain the aforementioned first object, a speaker according to a fifth aspect features, in addition to the configuration of the first aspect, in that the voice coil bobbin has air vents providing communication between the inside of the voice coil bobbin and the inside of the first divided vibration member. With this configuration, a flow of air is produced between the inside and the outside of the voice coil bobbin, which provides the cooling effect on the magnetic circuit, resulting in high resistance to input.
To attain the aforementioned first object, a speaker according to a sixth aspect features, in addition to the configuration of the first aspect, in that another diaphragm member is mounted so as to extend across the first divided vibration member and the second divided vibration member. With this configuration, the divided vibration of the first divided vibration member and the second divided vibration member is prevented, resulting in sound pressure properties for smooth output.
To attain the aforementioned second object, a method of assembling a speaker according to a seventh aspect of the present invention features steps of: assembling a magnetic circuit part including a magnetic circuit gap; mounting a voice coil bobbin, on which a voice coil is wound and which is coupled to a first divided vibration member making up a diaphragm member, to the magnetic circuit part so as to insert a portion of the voice coil bobbin on which the voice coil is wound into the magnetic circuit gap; attaching a frame to the magnetic circuit part; interposing a plurality of dampers between the frame and the first divided vibration member which is mounted to the magnetic circuit part through the voice coil bobbin; and mounting a second divided vibration member, which makes up the diaphragm member together with the first divided vibration member, between the first divided vibration member and the frame to which the dampers are attached.
According to the method of assembling the speaker of the seventh aspect, the diaphragm member vibrating to output sound is designed as a two-piece member. When the voice coil bobbin is joined with the magnetic circuit part constructed of a yoke and a magnet, the first divided vibration member linked to the voice coil bobbin is separated from the damper and an edge.
Hence, when the portion of the voice coil bobbin on which the voice coil is wound is inserted into the magnetic circuit gap formed in the magnetic circuit part, it is possible to reliably position the voice coil bobbin to the magnetic circuit gap. This eliminates the need for providing large dimensions for the magnetic circuit gap for assembling as in the prior art, and allows the dimensions to be set at the minimum values needed for vibration of the voice coil bobbin, resulting in the efficient configuration of the magnetic circuit.
Further according to the method of assembling, the two-piece member designed for the diaphragm member allows the speaker to be assembled while the individual parts are constructed sequentially in the single assembly line, which results in increasing the efficiency of the assembling operation.
To attain the aforementioned second object, a method of assembling a speaker according to an eighth aspect features, in addition to the configuration of the seventh aspect, a step of mounting another diaphragm member so as to extend across the first divided vibration member and the second divided vibration member after the step of mounting the second divided vibration member.
With this step, the divided vibration of the first divided vibration member and the second divided vibration member is prevented, resulting in sound pressure properties for smooth output.
To attain the aforementioned second object, a method of assembling a speaker according to a ninth aspect features, in addition to the configuration of the seventh aspect, in that the diaphragm member is a cone member.
With this configuration, the speaker using the vibration of the cone member for output can have a high efficient magnet circuit configuration and also an efficient assembling operation.